The conventional wrench is disclosed in U.S. Pat. No. 6,457,386 and comprises a main body, a drive shaft, a handle, a first annular gear, a second annular gear, a drive member, a pair of first pawls, a pair of second pawls, a rotating wheel, a control member, a plurality of balls, a plurality of compression springs, and a coiled spring. The main body has a through hole to receive the drive shaft, a pair of pivot holes, a groove to receive the drive member, a plurality of inner teeth, and the through hole communicating with the groove. The drive member has a through aperture and a chamber. The handle has a blind hole to receive the drive shaft. The first annular gear has a plurality of inner periphery serrations and a plurality of one-sided serrations. The second annular gear has a plurality of inner periphery teeth and a plurality of one-sided teeth. Each of the first pawls has a plurality of positioning recesses and a plurality of outer teeth. Each of the second pawls has a plurality of periphery serrations and a plurality of one-sided serrations. The rotating wheel has an oblong center hole. The control member has a pillar and a press disk disposed on the pillar. The pillar has a plurality of circular holes. Each of the circular holes of the pillar receives the corresponding compression spring and the corresponding ball. A pair of studs pass through the pivot holes of the main body and an annular recess of the drive shaft. The chamber of the drive member receives the first pawls and the second pawls. The first annular gear encloses one of the first pawls and one of the second pawls. The second annular gear encloses the other of the first pawls and the other of the second pawls. The pillar is inserted through the coiled spring, the oblong center hole of the rotating wheel, and the through aperture of the drive member. The coiled spring is disposed between the press disk and the rotating wheel, and each of the balls is engaged with one of the first pawls and the second pawls.
The main body has a through hole in which the drive shaft is pivotably located. However, the main body has a fixed length and the through hole has its length, the through hole is made by using a tool. Unfortunately, the cost for using the tool is by charged by the unit of mini-meter, so that when the length of the through hole has a certain length, cost for making the through hole will be high. Besides, the debris cannot be removed when making the through hole so that the drill of the tool may be broken during drilling.
Furthermore, the drive shafts and the through holes disclosed in FIGS. 1 and 4 of U.S. Pat. No. 6,457,386 have the similar problems.